ARCv2: Enable LOCKDEP

- The asm helpers for calling into irq tracer were missing

- Add calls to above helpers in low level assembly entry code for ARCv2

- irq_save() uses CLRI to disable interrupts and returns the prev interrupt
  state (in STATUS32) in a specific encoding (and not the raw value of
  STATUS32). This is usable with SETI in irq_restore(). However
  save_flags() reads the raw value of STATUS32 which doesn't pair with
  irq_save/restore() and thus needs fixing.

Signed-off-by: Evgeny Voevodin <evgeny.voevodin@intel.com>
[vgupta: updated changelog and also added some comments]
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

diff --git a/arch/arc/include/asm/irqflags-arcv2.h b/arch/arc/include/asm/irqflags-arcv2.h
index 37c2f751eebf03d8f9f16d997bacdcb5b8f6323f..d1ec7f6b31e0d986fe9fca340c5c46935008db70 100644 (file)
--- a/arch/arc/include/asm/irqflags-arcv2.h
+++ b/arch/arc/include/asm/irqflags-arcv2.h
@@ -18,6 +18,12 @@
 #define STATUS_AD_MASK         (1<<STATUS_AD_BIT)
 #define STATUS_IE_MASK         (1<<STATUS_IE_BIT)
 
+/* status32 Bits as encoded/expected by CLRI/SETI */
+#define CLRI_STATUS_IE_BIT     4
+
+#define CLRI_STATUS_E_MASK     0xF
+#define CLRI_STATUS_IE_MASK    (1 << CLRI_STATUS_IE_BIT)
+
 #define AUX_USER_SP            0x00D
 #define AUX_IRQ_CTRL           0x00E
 #define AUX_IRQ_ACT            0x043   /* Active Intr across all levels */
@@ -100,6 +106,13 @@ static inline long arch_local_save_flags(void)
        :
        : "memory");
 
+       /* To be compatible with irq_save()/irq_restore()
+        * encode the irq bits as expected by CLRI/SETI
+        * (this was needed to make CONFIG_TRACE_IRQFLAGS work)
+        */
+       temp = (1 << 5) |
+               ((!!(temp & STATUS_IE_MASK)) << CLRI_STATUS_IE_BIT) |
+               (temp & CLRI_STATUS_E_MASK);
        return temp;
 }
 
@@ -108,7 +121,7 @@ static inline long arch_local_save_flags(void)
  */
 static inline int arch_irqs_disabled_flags(unsigned long flags)
 {
-       return !(flags & (STATUS_IE_MASK));
+       return !(flags & CLRI_STATUS_IE_MASK);
 }
 
 static inline int arch_irqs_disabled(void)
@@ -128,11 +141,32 @@ static inline void arc_softirq_clear(int irq)
 
 #else
 
+#ifdef CONFIG_TRACE_IRQFLAGS
+
+.macro TRACE_ASM_IRQ_DISABLE
+       bl      trace_hardirqs_off
+.endm
+
+.macro TRACE_ASM_IRQ_ENABLE
+       bl      trace_hardirqs_on
+.endm
+
+#else
+
+.macro TRACE_ASM_IRQ_DISABLE
+.endm
+
+.macro TRACE_ASM_IRQ_ENABLE
+.endm
+
+#endif
 .macro IRQ_DISABLE  scratch
        clri
+       TRACE_ASM_IRQ_DISABLE
 .endm
 
 .macro IRQ_ENABLE  scratch
+       TRACE_ASM_IRQ_ENABLE
        seti
 .endm
 

diff --git a/arch/arc/kernel/entry-arcv2.S b/arch/arc/kernel/entry-arcv2.S
index c1264607bbff3dca457fd47b8f078b62993b7af7..7a1c124ff021d53377d24ff5d1bb9cccbb2831de 100644 (file)
--- a/arch/arc/kernel/entry-arcv2.S
+++ b/arch/arc/kernel/entry-arcv2.S
@@ -69,8 +69,11 @@ ENTRY(handle_interrupt)
 
        clri            ; To make status32.IE agree with CPU internal state
 
-       lr  r0, [ICAUSE]
+#ifdef CONFIG_TRACE_IRQFLAGS
+       TRACE_ASM_IRQ_DISABLE
+#endif
 
+       lr  r0, [ICAUSE]
        mov   blink, ret_from_exception
 
        b.d  arch_do_IRQ
@@ -169,6 +172,11 @@ END(EV_TLBProtV)
 
 .Lrestore_regs:
 
+       # Interrpts are actually disabled from this point on, but will get
+       # reenabled after we return from interrupt/exception.
+       # But irq tracer needs to be told now...
+       TRACE_ASM_IRQ_ENABLE
+
        ld      r0, [sp, PT_status32]   ; U/K mode at time of entry
        lr      r10, [AUX_IRQ_ACT]
 

diff --git a/arch/arc/kernel/entry-compact.S b/arch/arc/kernel/entry-compact.S
index 431433929189c8b63e8b3efe41ef03030fa8b86f..0cb0abaa0479e53ab1ea7ef8e45ab0cd42d2e965 100644 (file)
--- a/arch/arc/kernel/entry-compact.S
+++ b/arch/arc/kernel/entry-compact.S
@@ -341,6 +341,9 @@ END(call_do_page_fault)
 
 .Lrestore_regs:
 
+       # Interrpts are actually disabled from this point on, but will get
+       # reenabled after we return from interrupt/exception.
+       # But irq tracer needs to be told now...
        TRACE_ASM_IRQ_ENABLE
 
        lr      r10, [status32]